Combine chili powder, 1/2 teaspoon salt, pepper and sugar in a small bowl. Rub over both sides of steak. Leave at room temperature while preparing relish.

Heat 1 teaspoon oil in a heavy large skillet over medium-high heat. Add bell pepper and onion. Season with additional salt and cloves. Saute until tender, about 5 to 8 minutes. Remove from heat. Add vinegar. Return to heat and cook until liquid evaporates, about 2 minutes. Remove from heat.